Standardization works of international mobile telecommunication (IMT)-advanced which is a next generation (i.e., post 3rd generation) mobile communication system are carried out in the international telecommunication union radio communication sector (ITU-R). The IMT-advanced aims at support of an Internet protocol (IP)-based multimedia service with a data transfer rate of 1 Gbps in a stationary or slowly moving state or 100 Mbps in a fast moving state.
3rd generation partnership project (3GPP) is a system standard satisfying requirements of the IMT-advanced, and prepares LTE-advanced which is an improved version of long term evolution (LTE) based on orthogonal frequency division multiple access (OFDMA)/single carrier-frequency division multiple access (SC-FDMA) transmission. The LTE-advanced is one of promising candidates for the IMT-advanced. A technology related to a relay node is one of main technologies for the LTE-advanced.
A relay node (RN) is a device for relaying a signal between a base station (BS) and a user equipment (UE), and is used for cell coverage extension and throughput enhancement of a wireless communication system.
Many researches for a method of transmitting a signal between the BS and the RN are currently ongoing in the wireless communication employing the RN. A conventional method of transmitting a signal between the BS and the UE has a problem when a signal is transmitted between the BS and the RN.
For example, when using frequency division duplex (FDD) between a BS and a UE, a frequency band in which the BS transmits a downlink signal is distinguished from a frequency band in which the UE transmits an uplink signal. That is, since signals are transmitted/received between the BS and the UE at different frequency bands, there is no problem when transmitting/receiving signals simultaneously.
On the other hand, a frequency band in which the RN transmits an access downlink signal to a relay node-UE (RN-UE) may be identical to a frequency band in which the BS transmits a backhaul downlink signal to the RN. In addition, a frequency band in which the RN-UE transmits an access uplink signal to the RN may be identical to a frequency band in which the RN transmits a backhaul uplink signal to the BS. That is, when the wireless communication system employs the RN, the RN may have to receive or transmit signals at the same frequency band. It is assumed in this case that, it is difficult to transmit and receive signals simultaneously at the same frequency band due to self-interference. Therefore, the BS transmits/receives signals to/from the BS and the RN-UE by using time division multiplexing (TDM).
In addition, the RN may have to receive a signal from the BS after transmitting a control signal to the RN-UE linked to the RN in a subframe in which a signal is received from the BS. Therefore, a specific transient time or guard time may be necessary due to transmission/reception switching of a signal in a subframe.
Accordingly, there is a need for a method and apparatus for transmitting a control signal and data between a BS and an RN by considering an operational characteristic of the RN.